1. Field of the Invention
The present invention relates to an evaluation method and an evaluation system for a semiconductor storage device.
2. Description of the Related Art
JP-A 2002-343096 (KOKAI), for example, discloses an evaluation technique for evaluating durability (reliability) of a semiconductor memory module. Specifically, a test module, such as dual-in-line memory modules (DIMMs) in which semiconductor memories are mounted on a circuit board, is placed in a constant-temperature oven and connected to an evaluating personal computer (PC), and a control board is arranged corresponding to each DIMM. In this state, the evaluating PC performs continuous write/read accesses to the test module via the control boards and evaluates the reliability of the test module based on the result of the continuous write/read accesses.
In recent years, a solid state drive (SSD), which includes a semiconductor memory (a NAND-type flash memory) for data storage, is being increasingly used as the substitute to a hard disk drive (HDD) in host devices such as PCs. Consequently, it has become important to make sure that such a semiconductor storage device including a semiconductor memory has long-term reliability against repeated write/read accesses. However, not many techniques are available for evaluating the reliability of a semiconductor storage device at the time of manufacturing. Although the evaluation technique disclosed in JP-A 2002-343096 (KOKAI) can be used for evaluating an SSD, it is complicated as well as expensive to configure the control boards because the interface of an SSD is more complex than that of a DIMM. That leads to an increase in the manufacturing cost as well as an increase in the configuration space necessary for implementing the evaluation technique.
Thus, there has been a need for an evaluation technique that makes it possible to evaluate reliability of a semiconductor storage device at a low cost and in a smaller configuration space.